4.5hp evinrude outboard stopping above shift speed on a lake only

[Tygo]

So this is what happens:
When i am in a small canal the engine runs perfectly but when someone goes past me fast the engine nearly stops and when im going onto the lake with mid sized waves it just doesnt work above shift speed and sounds like its about to die

What could be the problem?

 

[racerone]

Classic running on 1 cylinder.-----Post results of a compression test.-----Test and see if spark jumps a gap of 3/8" on a test device.

 

[Tygo]

Classic running on 1 cylinder.-----Post results of a compression test.-----Test and see if spark jumps a gap of 3/8" on a test device.

i dont know how to do a compression test and how do i test the spark?
also are you sure it could be running on 1 cylinder? it runs fine when not on the lake, and in neutral it runs fine too
it also takes quite a few pulls to start

 

[matt167]

Without load, they run so smooth that you would never notice it not running on one cylinder. Or the cylinder could be weak and not fire under load

 

[Tygo]

Without load, they run so smooth that you would never notice it not running on one cylinder. Or the cylinder could be weak and not fire under load

it runs fine when theres no waves or anything, its just when theres waves it starts dying or barely runs

 

[airshot]

Without specific test results that were ask for, we can't help....even though we would like to !!

 

[racerone]

If it runs good in neutral , I guess there is nothing wrong.----Sorry , my mistake !

 

[tphoyt]

You could have some loose wiring thats causing it to run on one on one cylinder when it get rocked around. They can run great on one cylinder at idle. Need to do the testing.

 

[oldboat1]

Device like this, available for about $10 at an auto parts store:

Plugs removed. Testing strength of ignition system. Set for 3/8", and look for strong, sharp spark.

 

[Tygo]

Device like this, available for about $10 at an auto parts store:
View attachment 381206
Plugs removed. Testing strength of ignition system. Set for 3/8", and look for strong, sharp spark.

alright, ill try to find one

 

[Tygo]

by the way, i made this video of what happened when i increased the throttle on that lake, worked fine in other places connected to the lake

 

[Crosbyman]

did you do the electricals (all) on this engine did you adjust timing

it does not seem to fire at the proper time or is hesitant (bad condensers ???) dirty points ??

 

[airshot]

You have some engine work to do !!

 

[oldboat1]

sounds a little rough to my ear. Is the shaft length correct for the boat? That is, maybe a long(er) shaft is needed.

 

[racerone]

I do not believe these 4.5 HP ever came with breaker points.----Model # should be posted.

 

[Tygo]

I do not believe these 4.5 HP ever came with breaker points.----Model # should be posted.

E5BACSS

by the way im gonna buy a compression test thing soon

 

[Tygo]

sounds a little rough to my ear. Is the shaft length correct for the boat? That is, maybe a long(er) shaft is needed.

how would i know if its correct? also it goes around 17kmh when it does work

 

[oldboat1]

If that is your main motor, the anti cavitation plate should be roughly level with the bottom of the hull. In no case should the water depth be less than a few inches above the intake, if you can avoid it (thinking of rough seas....)